【摘要】 为分析河八王及后代基因组DNA甲基化水平和遗传模式变化,以河八王及其后代F₁和BC₁为材料,采用甲基化敏感扩增多态性技术（Methylation sensitive amplification polymorphism,MSAP）结合毛细管电泳技术（Capillary electrophoresis,CE）分析亲本及后代基因组DNA甲基化水平和遗传模式变化规律。结果表明:母本‘GT05-3256’的MSAP比率是59.6%,父本‘GXN1’则是60.5%,其杂交种F₁的MSAP比率是56.4%～59.0%,均低于双亲;BC₁的母本‘YC94-46’的MSAP比率是59.4%,父本‘T6-3’则是59.0%,BC₁MSAP比率是56.9%～69.8%,整体平均为62.8%,平均值高于双亲。BC₁世代总甲基化水平略高于F₁世代水平。F₁和BC₁基因组CCGG位点发生甲基化的方式整体上以内部胞嘧啶双链甲基化为主。在F₁和BC₁中均检测到70种甲基化类型,并进一步分为A、B、C、D和E等5大类,其中A类是亲本向杂交种的甲基化遗传类型;B类是去甲基化类型,表示杂交种相应于其亲本的甲基化减弱;C类是过或超甲基化类型,表示杂交种相应于其亲本的甲基化增强;D类是次甲基化类型,杂交后代甲基化水平比双亲均要低;E类为不定类型。结果显示,B、C、D、E是杂交种的甲基化变异类型;F₁的甲基化遗传类型（A类）比例明显低于BC₁,但变异类型B、C、D、E高于BC₁;杂交形成F₁和BC₁过程中,基因组DNA普遍发生了超甲基化修饰。更多还原

【Abstract】 In order to analyze the changes of DNA methylation level,the DNA methylation levels and genetic patterns in F₁,BC₁ and their parents were detected using methylation sensitive amplification polymorphism（MSAP） and capillary electrophoresis technology（CE）.The results showed that:MSAP ratios in the maternal parent GT05-3256,paternal parent GXN1 and in the hybrid F₁ were respectively 59.6%,60.5% and 56.4%-59.0%,showing the MSAP ratio in F1 was lower than that in the both parents;the MSAP ratios in the maternal parent YC94-46,paternal parent T6-3 and BC₁ were respectively 59.4%,59.0% and 56.9%-69.8% in with the average of 62.8%,showing that the MASP ratio of BC1 was higher than that in the both parents.The total methylation level in the BC₁ generation is slightly higher than that in the F₁ generation;the methylation of CCGG loci in sugarcane genome of the individuals in F₁ and BC₁ mainly occurred on the internal cytosine double-strand.A total of 70 different methylations were detected in the F₁ and BC₁ populations,and they were further divided into 5 types:type A,the methylation patterns in the hybrids were the same as their parents;type B,demethylation,the methylation in the hybrids was weaken compared to that in the parents;type C,hypermethylation,the methylation in the hybrids was enhanced corresponding to the parents;type D,hypomethylation,the degree of methylation in the hybrids was lower than that in the both parents;and type E,uncertain type.Among them,type A is the genetic transfer type from the parent to the hybrid,and types B,C,D and E are the methylation variants of the hybrids.The results showed that the rate of methylation type A in the F₁ individuals was significantly lower than that in the BC₁ while types B,C,D,and E were higher than those in the BC₁.In conclusion,during the F₁ and BC₁ hybridization,the hypermethylation occurred in the whole genome.更多还原